I may be mistaken about this, but weren't many of the people who fled to Canada and the USA considered cowardly by those who stayed? I read Nancy Mitford's books set in that era, and she had some scathing things to say about people who used children as a ticket out.

(I remember there was a popular song titled The King is still in London that lauded him for refusing to evacuate.)

There was also that story that when Parliament was considering leaving the capital, the King and Churchill wore Sten guns onto the floor and said that if nobody else would stay and fight, they would.